Objective:To study the effects of astaxanthin on osteoporosis of ovariectomized rat models. Methods:Seventy-two 15 weeks old SD rats were divided into six groups,included control group and five ovariectomized models. After model groups were fed by different dosage(20-15-10 mg/kg) astaxanthin for 12 weeks,related indexes were analyzed,including their length bone mineral density(BMD),bone mineral,serum estradiol,serum alkaline phosphatase(ALP) and uterus index. Results:Compared with model group,different dosage groups and nilestriol group could increase BMD,bone mineral,serum estradiol and uterus index,but decreased serum ALP(P < 0.05). Conclusion:As a female sex hormone-like component,astaxanthin may ameliorate the bone quality and inhibit osteoporosis of ovariectomized rat models.